scholarly journals Intestinal Carriage of Carbapenemase-Producing Organisms: Current Status of Surveillance Methods

2015 ◽  
Vol 29 (1) ◽  
pp. 1-27 ◽  
Author(s):  
Roberto Viau ◽  
Karen M. Frank ◽  
Michael R. Jacobs ◽  
Brigid Wilson ◽  
Keith Kaye ◽  
...  
Keyword(s):  
Infection Control ◽  
Clinical Performance ◽  
Low Cost ◽  
Turnaround Time ◽  
Nucleic Acid Amplification ◽  
Current Status ◽  
Content Type ◽  
Advantages And Disadvantages ◽  
Control And Prevention ◽  
Ready Availability

SUMMARYCarbapenemases have become a significant mechanism for broad-spectrum β-lactam resistance inEnterobacteriaceaeand other Gram-negative bacteria such asPseudomonasandAcinetobacterspp. Intestinal carriage of carbapenemase-producing organisms (CPOs) is an important source of transmission. Isolation of carriers is one strategy that can be used to limit the spread of these bacteria. In this review, we critically examine the clinical performance, advantages, and disadvantages of methods available for the detection of intestinal carriage of CPOs. Culture-based methods (Centers for Disease Control and Prevention [CDC] protocols, chromogenic media, specialized agars, and double-disk synergy tests) for detecting carriage of CPOs are convenient due to their ready availability and low cost, but their limited sensitivity and long turnaround time may not always be optimal for infection control practices. Contemporary nucleic acid amplification techniques (NAATs) such as real-time PCR, hybridization assays, loop-mediated isothermal amplification (LAMP), or a combined culture and NAAT approach may provide fast results and/or added sensitivity and specificity compared with culture-based methods. Infection control practitioners and clinical microbiologists should be aware of the strengths and limitations of available methods to determine the most suitable approach for their medical facility to fit their infection control needs.

scholarly journals Comparison of the Panther Fusion and BD MAX Group B Streptococcus (GBS) Assays for Detection of GBS in Prenatal Screening Specimens

2019 ◽  
Vol 57 (11) ◽  
Author(s):  
Gregory J. Berry ◽  
Fan Zhang ◽  
Ryhana Manji ◽  
Stefan Juretschko
Keyword(s):  
Late Onset ◽  
Clinical Performance ◽  
Group B Streptococcus ◽  
Turnaround Time ◽  
Nucleic Acid Amplification ◽  
Kappa Statistics ◽  
Loading Capacity ◽  
Content Type ◽  
Return Visits ◽  
Group B

ABSTRACT Streptococcus agalactiae or group B Streptococcus (GBS) is the cause of early- and late-onset GBS disease in neonates and can present as septicemia, meningitis, and pneumonia. Our objective was to compare the performance of two FDA-approved nucleic acid amplification tests (NAATs), the Panther Fusion and BD MAX systems, for detection of GBS in vaginal-rectal screening specimens. A total of 510 vaginal-rectal prepartum specimens were tested simultaneously in both NAATs following broth enrichment. Assay agreement was calculated using kappa statistics. Overall agreement between assays was 99.0% (505/510; 95% confidence interval, 0.951 to 0.997; kappa = 0.974). Discordant results were retested with both assays and by standard culture. The assays were also compared for workflow characteristics, including time to first results (TFR), total turnaround time (TAT), number of return visits to load additional specimens, and hands-on time (HoT). Using a standard run size of 60 specimens/day, the Panther Fusion assay had a longer TFR (2.4 versus 2.0 h) but showed a shorter overall TAT for all 60 samples (3.98 versus 7.18 h) due to an increased initial sample loading capacity, and it required less labor (35.0 versus 71.3 s/sample) and fewer return visits for loading additional specimens (0 versus 2). The Panther Fusion system also had a larger sample loading capacity (120 versus 24 samples) and greater 8-h throughput (335 versus 96 samples). In summary, the Panther Fusion GBS assay has clinical performance comparable to that of the BD MAX GBS assay but provides a faster TAT, less HoT, and higher throughput.

scholarly journals Performance Evaluation of the SAMBA II SARS-CoV-2 Test for Point-of-Care Detection of SARS-CoV-2

2020 ◽  
Vol 59 (1) ◽  
pp. e01262-20 ◽  
Author(s):  
Sonny M. Assennato ◽  
Allyson V. Ritchie ◽  
Cesar Nadala ◽  
Neha Goel ◽  
Cuijuan Tie ◽  
...  
Keyword(s):  
Public Health ◽  
Infection Control ◽  
Patient Management ◽  
Clinical Performance ◽  
Point Of Care ◽  
Turnaround Time ◽  
Control Measures ◽  
Nucleic Acid Amplification ◽  
Analytical Sensitivity ◽  
Percent Agreement

ABSTRACTNucleic acid amplification for the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA in respiratory samples is the standard method for diagnosis. The majority of this testing is centralized and therefore has turnaround times of several days. Point-of-care (POC) testing with rapid turnaround times would allow more effective triage in settings where patient management and infection control decisions need to be made rapidly. The inclusivity and specificity of the Simple AMplification-Based Assay (SAMBA) II SARS-CoV-2 test were determined by both in silico analyses of the primers and probes and wet testing. The SAMBA II SARS-CoV-2 test was evaluated for performance characteristics. Clinical performance was evaluated in residual combined throat/nose swabs and compared to that of the Public Health England real-time PCR assay targeting the RdRp gene. The SAMBA II SARS-CoV-2 test has an analytical sensitivity of 250 copies/ml for detecting two regions of the genome (open reading frame 1ab [ORF1ab] and nucleocapsid protein [N]). The clinical performance was evaluated in 172 residual combined nose/throat swabs provided by the Clinical Microbiology and Public Health Laboratory, Addenbrooke’s Hospital, Cambridge (CMPHL), which showed an estimated positive percent agreement of 98.9% (95% confidence interval [CI], 93.83 to 99.97) and negative percent agreement of 96.4% (95% CI, 89.92 to 99.26) compared to testing by the CMPHL. The data show that the SAMBA II SARS-CoV-2 test performs equivalently to the centralized testing methods, but with a shorter turnaround time of 86 to 101 min. Point-of-care tests such as SAMBA should enable rapid patient management and effective implementation of infection control measures.

scholarly journals Third-Generation Sequencing in the Clinical Laboratory: Exploring the Advantages and Challenges of Nanopore Sequencing

2019 ◽  
Vol 58 (1) ◽  
Author(s):  
Lauren M. Petersen ◽  
Isabella W. Martin ◽  
Wayne E. Moschetti ◽  
Colleen M. Kershaw ◽  
Gregory J. Tsongalis
Keyword(s):  
Infectious Disease ◽  
Pathogen Detection ◽  
Clinical Laboratory ◽  
Low Cost ◽  
Turnaround Time ◽  
Metagenomic Sequencing ◽  
Nanopore Sequencing ◽  
Advantages And Disadvantages ◽  
Disease Diagnostics ◽  
Infectious Disease Diagnostics

ABSTRACT Metagenomic sequencing for infectious disease diagnostics is an important tool that holds promise for use in the clinical laboratory. Challenges for implementation so far include high cost, the length of time to results, and the need for technical and bioinformatics expertise. However, the recent technological innovation of nanopore sequencing from Oxford Nanopore Technologies (ONT) has the potential to address these challenges. ONT sequencing is an attractive platform for clinical laboratories to adopt due to its low cost, rapid turnaround time, and user-friendly bioinformatics pipelines. However, this method still faces the problem of base-calling accuracy compared to other platforms. This review highlights the general challenges of pathogen detection in clinical specimens by metagenomic sequencing, the advantages and disadvantages of the ONT platform, and how research to date supports the potential future use of nanopore sequencing in infectious disease diagnostics.

scholarly journals Increased Clinical Specificity with Ultrasensitive Detection of Clostridioides difficile Toxins: Reduction of Overdiagnosis Compared to Nucleic Acid Amplification Tests

2019 ◽  
Vol 57 (11) ◽  
Author(s):  
Johanna Sandlund ◽  
Joel Estis ◽  
Phoebe Katzenbach ◽  
Niamh Nolan ◽  
Kirstie Hinson ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Patient Outcomes ◽  
Single Molecule ◽  
Clinical Performance ◽  
Neutralization Assay ◽  
Nucleic Acid Amplification ◽  
Content Type ◽  
Clostridioides Difficile ◽  
Health Care Associated Infections ◽  
Stool Specimens

ABSTRACT Clostridioides difficile infection (CDI) is one of the most common health care-associated infections, resulting in significant morbidity, mortality, and economic burden. Diagnosis of CDI relies on the assessment of clinical presentation and laboratory tests. We evaluated the clinical performance of ultrasensitive single-molecule counting technology for detection of C. difficile toxins A and B. Stool specimens from 298 patients with suspected CDI were tested with the nucleic acid amplification test (NAAT; BD MAX Cdiff assay or Xpert C. difficile assay) and Singulex Clarity C. diff toxins A/B assay. Specimens with discordant results were tested with the cell cytotoxicity neutralization assay (CCNA), and the results were correlated with disease severity and outcome. There were 64 NAAT-positive and 234 NAAT-negative samples. Of the 32 NAAT+/Clarity− and 4 NAAT−/Clarity+ samples, there were 26 CCNA− and 4 CCNA− samples, respectively. CDI relapse was more common in NAAT+/toxin+ patients than in NAAT+/toxin− and NAAT−/toxin− patients. The clinical specificity of Clarity and NAAT was 97.4% and 89.0%, respectively, and overdiagnosis was more than three times more common in NAAT+/toxin− than in NAAT+/toxin+ patients. The Clarity assay was superior to NAATs for the diagnosis of CDI, by reducing overdiagnosis and thereby increasing clinical specificity, and the presence of toxins was associated with negative patient outcomes.

scholarly journals Multicenter Diagnostic Accuracy Evaluation of the Luminex Aries Real-Time PCR Assay for Group B Streptococcus Detection in Lim Broth-Enriched Samples

2018 ◽  
Vol 56 (8) ◽  
Author(s):  
D. R. Hernandez ◽  
D. M. Wolk ◽  
K. L. Walker ◽  
S. Young ◽  
R. Dunn ◽  
...  
Keyword(s):  
Clinical Performance ◽  
Enrichment Culture ◽  
Culture Method ◽  
Nucleic Acid Amplification ◽  
Accuracy Evaluation ◽  
Culture Methods ◽  
Assay Sensitivity ◽  
Content Type ◽  
Group B ◽  
Positive Agreement

ABSTRACT The vertical transmission of group B Streptococcus (GBS) strains causing neonatal sepsis is one of the leading reasons for neonatal mortality worldwide. The gold standard for GBS detection is enriched culture with or without the aid of chromogenic agars. Given the high risk for morbidity and mortality in this population, high assay sensitivity is required to prevent the personal and economic costs of GBS disease. Nucleic acid amplification tests (NAATs) allow for objective determination of GBS colonization with a sensitivity and a specificity higher than those of traditional culture methods. In this study, we determined the analytical and clinical performance of the Aries GBS assay compared to those of the enrichment culture method, biochemical identification, and the NAATs used at the study sites. Remnant Lim broth samples were used to perform the Aries assay and reference testing. Upon first testing using enriched culture as the reference standard, the Aries GBS assay identified GBS with a 96.1% sensitivity (95% confidence interval [CI], 91.2 to 98.7%) and a 91.4% specificity (95% CI, 88.8 to 93.6%). The test performed with 100% positive agreement (95% CI, 83.2 to 100%) compared to the results of the BD Max GBS assay and 98.0% positive agreement (95% CI, 89.2 to 99.9%) compared to the results of the Cepheid Xpert GBS LB test. Repeatability and reproducibility were maintained in intra- and interlaboratory testing, regardless of the instrument, module, or user who performed the test. The Aries GBS assay can be set up in less than 5 min and produces results in 2 h. The easy setup, with minimal hands-on time, and high assay sensitivity and specificity make this a useful testing option for GBS screening in prepartum women.

scholarly journals Design and Validation of Transcription-Mediated-Amplification Nucleic Acid Amplification Tests forMycoplasma genitalium

2019 ◽  
Vol 57 (8) ◽  
Author(s):  
Brett Kirkconnell ◽  
Barbara Weinbaum ◽  
Katherine Santos ◽  
Trisha Le Nguyen ◽  
Bryan Vinluan ◽  
...  
Keyword(s):  
Clinical Performance ◽  
Mycoplasma Genitalium ◽  
Vaginal Swab ◽  
Nucleic Acid Amplification ◽  
Clinical Validation ◽  
Analytical Sensitivity ◽  
Reference Standard ◽  
Content Type ◽  
Sensitivity Specificity

ABSTRACTMycoplasma genitaliumis a sexually transmitted bacterium linked to adverse sexual and reproductive health outcomes in women and men.M. genitaliumis difficult to culture, and in the absence of validated amplified molecular methods for diagnosis of infection, there is no reference standard available for use as a comparator for the validation of newM. genitaliumdiagnostic tests. We evaluated the analytical and clinical performance of three transcription-mediated amplification (TMA) tests forM. genitalium, each targeting unique rRNA sequences, for use as a composite comparator for clinical validation of the AptimaMycoplasma genitalium(AMG) assay, anin vitrodiagnostic (IVD) TMA test that targets 16 s rRNA ofM. genitalium. Analytical sensitivity, specificity, and strain inclusivity of all four TMA tests were determined using nine laboratory strains ofM. genitaliumand 56 nontarget bacteria, protozoa, and viruses. Analytical sensitivity of the tests forM. genitaliumranged from 0.017 to 0.040 genome equivalents/ml. None of the nontarget organisms evaluated cross-reacted with any test. A composite comparator reference standard consisting of the 3 alternate (Alt) TMA tests was used to evaluate the clinical performance of the AMG assay by testing residual vaginal swab, female urine, and male urine specimens obtained from 1,400 adult subjects from three U.S. clinical sites. Using this reference standard to establish infected specimen status, the sensitivity, specificity, and overall agreement of the AMG IVD assay were 100%, 99.9%, and 99.9%, respectively. These results demonstrate the utility of molecular composite reference standard methodology for the clinical validation of future IVD tests for this organism.

Enhancing competitiveness through MNC-local firms co-opetitive relationships

2014 ◽  
Vol 4 (8) ◽  
pp. 1-6
Author(s):  
Audrey Catherine Depeige ◽  
Stavros Sindakis
Keyword(s):  
Market Share ◽  
Business Strategy ◽  
Low Cost ◽  
Strategy Management ◽  
Strategic Decision ◽  
Competitive Intelligence ◽  
Growth Strategies ◽  
Content Type ◽  
Advantages And Disadvantages

Subject area The case study reflects issues and challenges in the fields of strategy, management, competitive intelligence and new organizational designs. Study level/applicability The case study is recommended for MBA and postgraduate courses in strategy, management, competitive intelligence and new organizational designs. The case can also be used in executive development programs focusing on business strategy and innovation. Case overview It is 2009. LK Company has newly been established as lighting products manufacturer. Based in Thailand, the firm commences its business operations with an aggressive pricing strategy (low-cost products). At the time of the establishment and launch of operation activities, the market leader [an international multinational company (MNC)] has above 35 per cent market share, leaving LK with an initial 2 per cent market share. While the share of LK grew from 2 to 10 per cent in the past five years, competition in the industry nevertheless remains harsh. Companies are confronted with pressures to invest in the development of new energy-saving lamps, and in this context, LK's company executive board needs to make a strategic decision on which way to follow to sustain the business: shall this be with or without foreign MNCs. Expected learning outcomes Students will be able to better understand; analyze and assess the importance of resource management in highly competitive environments, as well as the importance of designing alternative growth strategies by identifying and assessing changes in the market/environment. They are introduced to characteristics of co-opetition strategies, advantages and disadvantages of co-opetitive business structures and impact of the choice of business partners over time. Supplementary materials Teaching notes are available for educators only. Please contact your library to gain login details or email [email protected] to request teaching notes.

scholarly journals Evaluation of the Liat Cdiff Assay for Direct Detection of Clostridioides difficile Toxin Genes within 20 Minutes

2019 ◽  
Vol 57 (6) ◽  
Author(s):  
David J. Hetem ◽  
Ingrid Bos-Sanders ◽  
Roel H. T. Nijhuis ◽  
Sven Tamminga ◽  
Livia Berlinger ◽  
...  
Keyword(s):  
Infection Control ◽  
Direct Detection ◽  
Point Of Care ◽  
Reference Method ◽  
Turnaround Time ◽  
Control Measures ◽  
Content Type ◽  
Infection Control Measures ◽  
Clostridioides Difficile ◽  
The Difference

ABSTRACT Clostridioides difficile is the main causative agent of antibiotic-associated diarrhea. Prompt diagnosis is required for initiation of timely infection control measures and appropriate adjustment of antibiotic treatment. The cobas Cdiff assay for use on the cobas Liat system enables a diagnostic result in 20 minutes. A total of 252 prospective (n = 150) and retrospective (n = 102) stool specimens from The Netherlands, France, and Switzerland were tested on the cobas Cdiff assay using the Xpert C. difficile assay as a reference method. The overall positive and negative percent agreement (PPA and NPA, respectively) of the cobas Cdiff assay compared with the Xpert C. difficile assay was 98.0% (100/102; 95% confidence interval [CI], 93.1% to 99.5%) and 94.0% (141/150; 95% CI, 89.0% to 96.8%), respectively. When comparing the PPAs of cobas Cdiff and Xpert C. difficile with culture, the results were 91.7% (55/60; 95% CI, 81.9% to 96.4%) and 85.0% (51/60; 95% CI, 73.9% to 91.9%), respectively. The difference was not statistically significant. The cobas Cdiff assay offers a very rapid alternative for diagnosing C. difficile infection. The 20-minute turnaround time provides the potential for point-of-care testing so that adequate infection control measures can be initiated promptly.

scholarly journals Alternate Nucleic Acid Targets Can Be Used To Create a Composite Standard To Evaluate Clinical Performance of Nucleic Acid Amplification Tests

2019 ◽  
Vol 57 (8) ◽  
Author(s):  
Julius Schachter ◽  
Max Chernesky
Keyword(s):  
Nucleic Acid ◽  
Clinical Performance ◽  
Mycoplasma Genitalium ◽  
Nucleic Acid Amplification Test ◽  
Nucleic Acid Amplification ◽  
Reference Standard ◽  
New Paradigm ◽  
Content Type ◽  
Nucleic Acid Amplification Tests ◽  
Link Type

ABSTRACTEvaluating the clinical performance of a new nucleic acid amplification test (NAAT) forMycoplasma genitalium, B. Kirkconnell, B. Weinbaum, K. Santos, T. Le Nguyen, et al. (J Clin Microbiol 57:e00264-19, 2019,https://doi.org/10.1128/JCM.00264-19) created 3 alternate NAATs that detected other uniqueM. genitaliumgene targets. Lacking a reference standard, they used the consensus of results with those 3 NAATs as the comparator. This approach could be a new paradigm to evaluate new NAATs when there is no previously defined reference standard.

Prescribers’ and dispensers' views about generic medicines and international non-proprietary name prescribing – a mixed methods study in Portugal

2020 ◽  
Vol 14 (2) ◽  
pp. 177-199
Author(s):  
Micaela Pinho
Keyword(s):  
Design Methodology ◽  
Low Cost ◽  
Nonparametric Tests ◽  
Mixed Methods Study ◽  
Generic Medicines ◽  
Content Type ◽  
Advantages And Disadvantages ◽  
Self Administered Questionnaire ◽  
Excessive Number ◽  
Level Of Agreement

Purpose This study aims to explore the views of pharmacy professionals (PPs) in Portugal about generic medicines and international non-proprietary name (INN) prescribing and compare them with the views of general practitioners (GPs). Design/methodology/approach A self-administered questionnaire was used to collect data from a sample of 185 community PPs and 85 GPs. Their perceptions were examined using a five-point Likert scale applied to statements focusing on five main topics of interest: motivation, safety, users’ perceptions and knowledge, advantages and disadvantages of generic medicines and INN prescribing. Daily experiences and suggestions for decreasing health and pharmaceutical expenses were explored through open-ended questions. Nonparametric tests were used to compare attitudes between both groups and to explore associations between the level of agreement and respondents’ demographic characteristics. Content analysis was used to categorize the answers to the open-ended questions. Findings Generally, GPs expressed more negative opinions toward generics and INN prescribing than PPs. GPs perceived generics as less effective, less safe, inferior in quality, more likely to cause side effects and believed that users do not trust them. Both groups believed that patients remain very confused and ill-informed about generics, only adhering to them because of their low cost and expressed concerns about the existence of an excessive number of generic medicines and the lack of patients’ responsibility toward medicines costs. Originality/value To the best of the authors’ knowledge, this study represents the first attempt to elicit and compare Portuguese GPs and PPs opinions concerning INN prescribing.

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